Over the decades there have been lots of movies about aliens landing on earth, and the possible outcomes, from the aggressors of War of the Worlds, to the sympathetic aliens of Alien Nation. One of the newest is reviewed on the SF/Fantasy movie site:

All these different scenarios beg discussion. Which movie do you think came closest to showing what it would really be like?I really like District 9, and I think Neill Blomkamp got pretty nearly right. But then I loved Morons from Outer Space as well, and the idea of our 'visitors' being stupid tourists. Anyone else want to offer their thoughts?